New cluster not able to start after reboot

Hi, I am trying to install a single node cluster for testing purpose. I am using an EC2 instance Ububtu 14.04 and MapR5.2. The installation with the web-based installer is pretty straight forward and went smoothly. I was able to play around with the MapR services. However, if I reboot the system. The cluster is not coming up. As far as I know, the cluster should come up automatically. So I check with "service mapr-zookeeper status" and "service mapr-warden status". Zookeeper seems okay, but for warden, the following is shown:

/opt/mapr/pid/warden.pid exists with pid 4377 but no WARDEN.

Then I tried to restart warden by "service mapr-warden restart" the following is shown:

Still no luck after restarting, so I check the /opt/mapr/logs directory for more information. I found that every time I try to restart warden, a new warden log file is created instead of appending to the end of the original one. I check the log in the latest "warden.log.8" , the content is as the following:

Stop wardenWARDEN not running.looking to stop mapr-core processes not started by wardenCLDB not running.Waiting up to 30 seconds ...Wed Mar 8 07:44:29 UTC 2017Start warden

I have deleted the instance and retry, I think the problem is when I restart the instance, the IP address have changed making the services cannot start correctly. I will try in a VM environment instead later, will grab and post the log here if the same problem appear